1. Field of the Invention
This invention relates to a cartridge/carrier locking device for an automatic gun.
2. Description of the Prior Art
In general, an automatic gun is arranged to perform an automatic loading operation after the gun has been fired, which operation includes the steps of extracting an empty cartridge by backward movement of a breechblock which normally closes the breech face of the barrel, returning the trigger device to its state of preparation for the next firing whilst concurrently the next cartridge is brought out of a magazine and moved toward the chamber of the barrel by an upward sway of a carrier, and loading the next cartridge into the chamber by the forward movement of the breechblock. This series of steps (hereinafter referred to as a cyclic reloading operation of the automatic gun) is accomplished in an extremely short period of time. From the safety viewpoint, it is important that after firing the gun there is a time delay to ensure that the spent cartridge is completely ejected from the receiver containing a trigger device, etc. by an extractor before the next cartridge is pushed up by the carrier towards the breech. In view of the importance of such a delay, an often-used arrangement includes a cartridge lock which normally is attached to the receiver and is used to prevent the next cartridge from leaving the magazine, the cartridges being urged out of the magazine by a spring disposed therewithin. The cartridge lock is released to allow the next cartridge to leave the magazine only when the breechblock fully retracts. In addition, there has to be provided a cartridge locking latch to allow locking of the cartridge lock, and a carrier locking latch which prevents the carrier from making the upward sway until the breechblock has sufficiently retracted to complete ejection of the preceding cartridge and the next cartridge is fully on the carrier.
However, the above described known arrangement requires many component parts and results in a complex construction. In addition to this drawback, it is necessary to have some means for releasing the carrier from the carrier locking latch in order to load the magazine with cartridges, because otherwise the carrier cannot be moved out of the way. This also has been a drawback of some designs.
A study of various prior art automatic reloading firearms has revealed the following points.
(1) When the breechblock has retracted fully inside the receiver and begins to move forward under the action of a recoil spring provided for instance in the stock, so as to return to its initial position, the forward movement of the breechblock urges the carrier to pivot and sway upward to move the next cartridge towards the breech. The pivotting force on the carrier is exerted only by the forward movement of the breechblock. PA1 (2) The restriction on the upward swaying movement of the carrier by a carrier lock is required only until the next cartridge is brought out of the magazine, the breechblock then starting to urge the carrier to move. PA1 (3) Since the barrel chamber must be loaded with the next cartridge shortly after the ejection of the empty cartridge, the next cartridge must be released from the cartridge lock at a stage prior to such loading, though at all other times the cartridge lock must be effective. PA1 (4) Heretofore, for a pivoting carrier, release thereof has been effected by pushing the carrier latch with the bottom rim of the cartridge itself as the cartridge is brought on to the carrier.
The inventor thus has discovered that the best result can be obtained by releasing the cartridge lock either when the retraction of the breechblock reaches about a maximum stroke or slightly earlier than that and, at the same time, by restricting the upward sway of the carrier due to the urging force of the breechblock until the cartridge is completely brought onto the carrier. This discovery has led to the present invention.
Strict restriction on the upward pivoting motion of the carrier is required only during a process of bringing a next cartridge out of the magazine onto the carrier. Naturally, no cartridge lock is required during this process. Assuming that the condition in which the cartridge and the carrier are respectively locked by locking devices is a positive state and the condition in which they are not locked is a negative state, the two locking devices should be in a reversed positive-negative functioning relation. This functional relation between the two locking devices can be satisfied by adapting a single latch plate to move in a seeesaw like manner.